001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 /*
019 * $Id: WriterChain.java 468654 2006-10-28 07:09:23Z minchau $
020 */
021 package org.apache.xml.serializer;
022
023 import java.io.IOException;
024
025 /**
026 * It is unfortunate that java.io.Writer is a class rather than an interface.
027 * The serializer has a number of classes that extend java.io.Writer
028 * and which send their ouput to a yet another wrapped Writer or OutputStream.
029 *
030 * The purpose of this interface is to force such classes to over-ride all of
031 * the important methods defined on the java.io.Writer class, namely these:
032 * <code>
033 * write(int val)
034 * write(char[] chars)
035 * write(char[] chars, int start, int count)
036 * write(String chars)
037 * write(String chars, int start, int count)
038 * flush()
039 * close()
040 * </code>
041 * In this manner nothing will accidentally go directly to
042 * the base class rather than to the wrapped Writer or OutputStream.
043 *
044 * The purpose of this class is to have a uniform way of chaining the output of one writer to
045 * the next writer in the chain. In addition there are methods to obtain the Writer or
046 * OutputStream that this object sends its output to.
047 *
048 * This interface is only for internal use withing the serializer.
049 * @xsl.usage internal
050 */
051 interface WriterChain
052 {
053 /** This method forces us to over-ride the method defined in java.io.Writer */
054 public void write(int val) throws IOException;
055 /** This method forces us to over-ride the method defined in java.io.Writer */
056 public void write(char[] chars) throws IOException;
057 /** This method forces us to over-ride the method defined in java.io.Writer */
058 public void write(char[] chars, int start, int count) throws IOException;
059 /** This method forces us to over-ride the method defined in java.io.Writer */
060 public void write(String chars) throws IOException;
061 /** This method forces us to over-ride the method defined in java.io.Writer */
062 public void write(String chars, int start, int count) throws IOException;
063 /** This method forces us to over-ride the method defined in java.io.Writer */
064 public void flush() throws IOException;
065 /** This method forces us to over-ride the method defined in java.io.Writer */
066 public void close() throws IOException;
067
068 /**
069 * If this method returns null, getOutputStream() must return non-null.
070 * Get the writer that this writer sends its output to.
071 *
072 * It is possible that the Writer returned by this method does not
073 * implement the WriterChain interface.
074 */
075 public java.io.Writer getWriter();
076
077 /**
078 * If this method returns null, getWriter() must return non-null.
079 * Get the OutputStream that this writer sends its output to.
080 */
081 public java.io.OutputStream getOutputStream();
082 }